Do I need to research family members who are not direct ancestors?

Who to Include in Your Family Tree

If you think that your direct ancestors changed their surname from an unknown name or you cannot find their town of origin, researching collateral or indirect ancestors might be of assistance. Researching your collateral relatives might help you find your family origins and lead you to more direct ancestors.

Jacobson and Jacobson Genealogy Researchers  https://www.bocafengshui.com/genealogy.html expert Jewish Galician Genealogy Researchers.